#define MAX_COLORS 10

#define CLAMP_STEP 0
#define SMOOTH_STEP 1

vec4 linearGradient(
  int amount,
  vec4 colors[MAX_COLORS],
  float stops[MAX_COLORS],
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec2 fragCoord = destCoord();

  vec2 dt = end - start;
  vec2 pt = fragCoord - start;
  float t = dot(pt, dt)/ dot(dt, dt);

  vec4 color = colors[0];
  for (int i = 1; i < amount; i++) {
    color = mix(
      color,
      colors[i],
      int(mixStep) == CLAMP_STEP
        ? clamp((t - stops[i - 1]) / (stops[i] - stops[i - 1]), 0.0, 1.0)
        : smoothstep(stops[i - 1], stops[i], t)
    );
  }
  return color;
}

kernel vec4 linearGradient1Kernel(
  __color color0,
  float stop0,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;

  float stops[MAX_COLORS];
  stops[0] = stop0;

  return linearGradient(1, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient2Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;

  return linearGradient(2, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient3Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;

  return linearGradient(3, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient4Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;

  return linearGradient(4, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient5Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;

  return linearGradient(5, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient6Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  __color color5,
  float stop5,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;
  colors[5] = color5;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;
  stops[5] = stop5;

  return linearGradient(6, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient7Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  __color color5,
  float stop5,
  __color color6,
  float stop6,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;
  colors[5] = color5;
  colors[6] = color6;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;
  stops[5] = stop5;
  stops[6] = stop6;

  return linearGradient(7, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient8Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  __color color5,
  float stop5,
  __color color6,
  float stop6,
  __color color7,
  float stop7,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;
  colors[5] = color5;
  colors[6] = color6;
  colors[7] = color7;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;
  stops[5] = stop5;
  stops[6] = stop6;
  stops[7] = stop7;

  return linearGradient(8, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient9Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  __color color5,
  float stop5,
  __color color6,
  float stop6,
  __color color7,
  float stop7,
  __color color8,
  float stop8,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;
  colors[5] = color5;
  colors[6] = color6;
  colors[7] = color7;
  colors[8] = color8;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;
  stops[5] = stop5;
  stops[6] = stop6;
  stops[7] = stop7;
  stops[8] = stop8;

  return linearGradient(9, colors, stops, start, end, mixStep);
}

kernel vec4 linearGradient10Kernel(
  __color color0,
  float stop0,
  __color color1,
  float stop1,
  __color color2,
  float stop2,
  __color color3,
  float stop3,
  __color color4,
  float stop4,
  __color color5,
  float stop5,
  __color color6,
  float stop6,
  __color color7,
  float stop7,
  __color color8,
  float stop8,
  __color color9,
  float stop9,
  vec2 start,
  vec2 end,
  float mixStep
) {
  vec4 colors[MAX_COLORS];
  colors[0] = color0;
  colors[1] = color1;
  colors[2] = color2;
  colors[3] = color3;
  colors[4] = color4;
  colors[5] = color5;
  colors[6] = color6;
  colors[7] = color7;
  colors[8] = color8;
  colors[9] = color9;

  float stops[MAX_COLORS];
  stops[0] = stop0;
  stops[1] = stop1;
  stops[2] = stop2;
  stops[3] = stop3;
  stops[4] = stop4;
  stops[5] = stop5;
  stops[6] = stop6;
  stops[7] = stop7;
  stops[8] = stop8;
  stops[9] = stop9;

  return linearGradient(10, colors, stops, start, end, mixStep);
}